Start by peeling the skin off your bananas and placing them in a clean bowl. Now, mash with a mixer or with a fork. Mix until it's soft and supple. Now, add your vanilla extract and add some oil into the banana mix. Add your buttermilk, add your eggs and mix once more.
Mix until the ingredients are evenly mixed. Next, add some peanut butter and stir. Now is the time to add your sugar to the bowl. Next, sieve your all-purpose flour into the paste. Add baking powder, baking soda and some salt. Now, gently sieve them into the paste.
Next, grate some nutmeg into the paste and mix them together. Mix until it's soft and supple.
In a non-stick spray pan, sprinkle light oil onto the pan and add your paste to the pan. Also add your remaining paste into another oil-sprinkled non-stick pan. Now, pour some peanuts into a sealing bag and gently seal it. Now, use a flour roller or any wooden kitchen utensil of your choice, could be a pestle – to gently mash the peanuts into bits.
When you're done, sprinkle the peanuts onto the paste and do the same for the other pan.
Bake at 350 degrees Fahrenheit (ca. 177 °C) or 175 degree Celsius for 30 minutes. Take the cake off the oven. Your delicious banana cake is ready to be eaten.